Horses (all horses) need 1.5%-3% of their body weight in forage per day as a base for their diets.
Horses like most any veggy or even some fruits. But, make sure that you check with your horse(s) vet, before giving it to them.
Horses all have different personalities, and can be aggressive towards or fearful of different things at any given time. Often, aggression stems from fear, and this is usually linked to a bad experience in the past. So, depending on the horse, some may be more fearful than others, just like humans. Some things that they can be fearful of include noisy/loud things or things in motion (plastic bags, cars). A mare can be quite aggressive around her foal and may make moves towards you if you get too close to the foal. Also horses in a semi wild state - by learned behavior of associating food with people, (by being feed or scavenging for food) can act in an aggressive manner if they are not given food, that they can smell. Beware picnics around semi wild horses! Horses are mainly fearful by nature. They are prey animals, and are always on the lookout for danger.
------- Horses are herd animals, most of their reactions are mirrors to the head of the heard, often their person. I would think mostly fearful! horses are mostly lovely creatures!! Most horses are fearful by nature as they are prey animals, but an Alpha horse and those vying for herd leader can be aggressive with other horses and with their handlers.
Mustang horses mainly eat grass.
Grease is used as a conditioner on dry hooves. It keeps the hooves from drying & cracking.